Schottky barrier contact on In0.53Ga0.47As with short-wave infrared transparent conductive oxide

Abstract

In this study, we fabricate and investigate Schottky barrier contact on n- and p-type In0.53Ga0.47As with transparent conductive oxide (TCO) that transmits light from the visible to short-wave infrared (SWIR) region. The TCO/p-In0.53Ga0.47As contact exhibits explicit rectifying behavior in current–voltage measurement, with an effective Schottky barrier height of 0.587 eV (I–V) and 0.567 eV (C–V). Conversely, the TCO/n-In0.53Ga0.47As exhibits the Ohmic behavior. From high-resolution transmission electron microscopy observations, we identified two types of interfacial layers between TCO and InGaAs: an In/Ga-rich InGaAs oxide layer and an In/Ga-deficient InGaAs layer. These interfacial layers may have a significant impact on the performance of the Schottky barrier contact. An ultra-thin Ni-layer insertion at the TCO/n+-InGaAs interface reduces the contact resistivity by more than an order of magnitude while maintaining high transparency. The TCO/p-InGaAs Schottky barrier contact also performs broadband light detection from the visible to SWIR region in a front-side illumination manner, which is highly promising for detecting wavelengths covering the optical communication band.